While you can use check constraints to enforce the use of specific fields, this isn't natively supported in Django, so you'll need to write your own migrations to accomplish this.Ī better way to address this shortcoming is by writing Django validation rules to enforce the structure you want.
I've already mentioned that it takes slightly longer to write data to jsonb fields than json because the JSON string must be converted to binary, but there are other reasons to avoid jsonb fields.įirst, if your data needs to enforce a strict schema, JSON may not be an ideal choice. It's worth noting that jsonb fields come with some drawbacks. There are many other ways to filter queries using JSON fields, so be sure to check out the official Django docs for more. You have to use the specific JSON operators and functions, so queries on JSON data look different from other Postgres queries.įor example, if you stored the following data in a Postgres table called profiles: idĪnd you wanted to query all users who have opted into your daily_email, you'd write a query like this: The query syntax for accessing JSON in Postgres is not typical SQL. This makes jsonb the preferred format for most JSON data stored in Postgres, and the typical choice for Django applications. It also allows you to index jsonb fields. While this means that writes are slightly slower, querying from jsonb fields is significantly faster. Unlike json fields, jsonb fields are stored in a binary structure rather than text strings. Postgres introduced jsonb in 9.4 to combat this issue. The problem was that json data was stored as a special kind of text field, so it was slow to query. This new data type allowed you to store JSON directly in your database and even query it. The json data type was added in Postgres 9.2 and enhanced in 9.3. JSON support is powerful, but because it comes in two types ( json and jsonb), it's helpful to understand which is the right choice for your application. JSON support in Postgres gives you the flexibility of a document store database like Mongo with the speed and structure of a relational database.
0 kommentar(er)
